Shoe sole fastening method



Sept. 11, 1962 w. T. LA ROSE SHOE SOLE FASTENING METHOD 3 Sheets-Sheet 1 Filed Nov. 10, 1960 5 J RM 0 m A a MA M w v [Z A a I 3 WIIII v d I J I Sept. 11, 1962 W. T. LA ROSE SHOE SOLE FASTENING METHOD Filed NOV. 10, 1960 Tic. 2:.

3 Sheets-Sheet 2 Sept. 11, 1962 w. T. LA ROSE SHOE SOLE FASTENING METHOD Filed NOV. 10, 1960 5 Sheets-Sheet 3 INVENTOR. MAL/AM [[4 $4M BY United States atent 3,952,953 Patented Sept. 11, 1952 ice 3,452,903 SHOE SQLE FASTENING h [ETH'SD William T. La Rose, 424 3rd Ave, Troy, NY. Filed Nov. 10, 1960, Ser. No. 68,424 8 Claims. (Cl. 12-142) The present invention relates to methods of fastening shoe soles to the shoe welt and the upper and more particularly to means for fastening .a plastic sole to a plastic welt.

More particularly still the method of the present invention utilizes a radio frequency heating apparatus and provides a bead on either the sole or the welt which bead concentrates the capacitive field and thus the heat, thereby assuring a permanent even fusion of the sole to the welt.

The present invention is particularly applicable when soles of plastic material are used. In general the shoe welt is formed of the same material as the sole and is attached to the shoe in any suitable manner as for example by sewing, nailing, electronic fusing or cementing.

It is an object of the invention to provide a method of attaching a plastic sole to a plastic welt or upper through the use of radio frequency heating apparatus.

It is another object of the invention to provide a bead extending completely around either the sole or welt adjacent the outer edge thereof in order to concentrate the heat provided by the radio frequency heating apparatus to thereby assure complete fusion between the sole and welt while at the same time providing for efiicient utilization of the radio frequency power.

Other objects and features of the invention will be apparent when the following description is considered in connection with the annexed drawings, in which,

FIGURE 1 is a top plan view of the radio frequency heating apparatus in accordance with my invention showing particularly the manner in which the electrodes of the radio frequency heatin circuit are moved into position about the upper of the shoe and bearing against the upper surface of the shoe welt so as to provide a force pressing the welt toward the sole.

FIGURE 2 is a fragmentary front elevational view of the apparatus of FIGURE 1 further illustrating the mode of operating the two-part electrodes into position adjacent the shoe upper;

FIGURE 2a is an enlarged View of the operating means for the electrodes;

FIGURE 3 is a top plan view of the lower electrodes showing the manner of operating these two-part electrodes into position to surround the bottom and sides of the shoe soles;

FIGURE 4 is an exploded perspective view of a shoe sole, welt and upper, illustrating particularly the location of a bead on the sole facing the welt; and

FIGURE 5 is a composite view showing a schematic diagram of a radio frequency oscillator together with a cross-sectional view of two pairs of upper and lower electrodes with shoe uppers and soles in position to be operated upon. This view likewise shows electrodes of the lefthand pair in a closed position ready for application ofheat and the electrodes of the righthand pair in an open position with the shoe sole and upper in position preparatory to closing the electrodes.

The heating apparatus of the present invention is, in its broad aspects, well known. It comprises, as shown in schematic form in FIGURE 5, a vacuum tube 10 of usual three-element type, in this instance having a filamentary cathode. The vacuum tube is connected in a circuit so that energy is fed back from the output to the input circuit forming a well known vacuum tube oscillator. In the present instance this is a modified Colpitts oscillator. The oscillator delivers high frequency power to a load circuit which includes the upper grounded electrode 11 and the lower electrode 12.

As is common in radio frequency dielectric heating apparatus, the electrodes are shaped to form a gap therebetween in the area where the heat is to be concentrated and the material to be heated is an electrical dielectric which thereby causes the electrical energy present in the capacitive field to be concentrated in a small area of the dielectric material.

In the particular instance, a lower electrode 12 is formed with a cavity 13 therein in which cavity the shoe sole 14 is placed. The electrode is made in two parts designated 12a and 12:; (FIG. 5) for convenient loading and unloading. Different sizes of electrodes are provided for different sizes of shoes. A non-metal member 19 extends the side walls of cavity 13 upwardly to prevent any of the plastic welt or sole squeezing out during the few seconds while they are fusing together.

In a similar manner the upper electrode 11 is made in two parts 11a and 11b (FIG. 5), the electrodes being shaped as indicated particularly at 15a and 15b to lie above the welt 16.

Referring now to FIGURES 1, 2 and 2a, the upper electrodes 11a and 1117 are mounted on frame members 17 and 18 and suitable means are provided for moving the electrodes of each pair towards and away from each other, the electrodes also moving downwardly after they make contact with each other. These means include the stub shafts .243 rotatably supported in the upstanding frame member 17 or 18. Mounted on each of the shafts 20 is a crank disk 21, the disks associated with each pair of electrodes being joined by a common handle 22.

Pivotally mounted near the periphery of each disk 21 is a pair of connecting rods 23 and 24, FIGURE 2a. These connecting rods at their ends remote from disk 21 are connected by means of pins 25 and 26 respectively to disks 27 and 23. The disks 27 and 28 are rotatably mounted in frame members 17 or 18. Each disk has a slot extending radially inwardly therefrom and pins 36 and 31 respectively fixed to the electrode halves 11d and 11b extend into these slots. Pins 38 and 31 also extend into the Z-shaped slots 32 and 33 in the corresponding frame mem ber 17 or 18.

Thus as the handle 22 is operated from the position shown at the left in FIGURE 2 to that shown at the right in that figure, disks 27 and 28 are likewise rotated and the electrode halves move first horizontally and then downwardly being guided by the slots 32 and 33. It should be noted at this point that rods 34 are fixed in portions such as the half 11b of the electrodes and extend into bores in the mating half 11a. By this means the electrodes are kept in a horizontal plane as they move inwardly and downwardly.

Connecting rods 23 and 24 are made in two parts in order that a spring pressure may be exerted in a downward direction when the handle is operated to its fullest extent. Referring now particularly to FIGURE 2a and to connecting rod 23, it will be seen that this rod is formed of a portion and a portion 36. Portion 36 slides in a bore in part 35 and is formed with a Washer or shoulder 37 thereon against which a compression spring 38 seats. Thus as the electrodes move downwardly the tips thereof engage the welt While the spring is fully extended and the springs are compressed as the electrode moves into its final position thus exerting a spring pressure in a downward direction and pressing the welt firmly against the sole or more accurately against a head on the sole.

As is clearly shown in FIGURE 5, when the upper electrodes 15a and 15b are closed together the lower generally pointed portions thereof will overlie the welt 16 hearing against the shoe upper designated 42 at the juncture with the welt.

As has been indicated hereinabove, the lower electrodes are also formed in two halves 12a and 12b and are separable in order that the machine may be conveniently loaded and unloaded. The electrodes are removable for different sizes to be operated upon in the same machine. The means for separating the two halves of the lower electrodes is illustrated in FIGURES 1 and 3. Referring particularly to FIGURE 3, these means comprise a crank disk 43 rotatably mounted on a side extension 44 of the outer electrode half of each pair. Disk 43 is provided with a handle 45 in order that it may be rotated for positioning the electrodes. Each disk 43 has pivotally mounted thereon adjacent its'periphery and at diametricallyopposite points the two connecting rods 46 and 47.

Pivotally mounted on brackets 48 and 50 are links 51 and 52, respectively, the righthand ends of these links 7 being pivotally connected to the outer ends of the respective connecting rods 46 and 47. Mounted on the electrode half 12b are two brackets 53 and 54. On these brackets links 55 and 56 are respectively pivoted. Links 51 and 55 are pivotally connected at their ends, the pivot pin 57 being extended downwardly and lying in a slot 58 in the base plate. -In a similar manner links 52 and 56 are pivotally connected by means of a pin 60 which extends downwardly and into a slot 61 in the base plate. Thus as handle 45 is moved from the position shown at the right of FIGURE 3 to that shown at the left the connecting rods 46 and 47 move rearwardly and forwardly causing the pivot pins 58 and 60 to move toward each other and of course causing the electrode halves 12a and 12b to move apart and into the position shown at the left in FIGURES 3 and 5.

As has been indicated, either the sole 14- or the welt 16 is formed with a head 62 which extends entirely around the periphery of the sole adjacent its outer edge. As shown in FIGURE 4, this bead is formed on the sole. It

will of course, as is indicated in FIGURE 4, lie against the electric repersented by the bead 62. The bead will therefore be softened and will fuse to both the sole and welt over an extended area thereof inwardly of the outer periphery. Suitable means are provided for energizing the oscillator for the period of time necessary to effect this softening after which the oscillator is deenergized resulting in substantially immediate cooling of the heated bead and adjacent portions of sole and welt and permanently attaching the sole to the welt. Thereupon the pairs of electrodes are separated and the pair of shoes comprising the left and right-hand shoes as shown in the drawings can be removed and the operation repeated.

While I have described a preferred embodiment of my invention, it will be understood that modifications thereof may readily be devised. I wish therefore to be limited A. not by the foregoing description, but solely by the claims granted to me.

What is claimed is:

1. The method of fastening a plastic shoe sole to a plastic shoe welt which comprises forming an integral bead on at least one of the welt and sole adjacent the periphery thereof, said bead facing the other of said welt and sole, placing the sole and welt in alignment with the bead therebetween, placing an electrode above the welt and a second electrode against the sole adjacent the periphery thereof and passing a radio frequency heating current through the peripheral portion of the sole and welt and through said bead to thereby fuse the welt to the sole.

2. The method of fastening a plastic shoe sole to a plastic shoe welt which comprises forming an integral head on at least one of the welt and sole adjacent the periphery thereof, said bead facing the other of said welt and sole, and extending throughout the entire periphery thereof,

placing the sole and welt in alignment with the bead' therebetween, placing an electrode above the welt and a second electrode against the sole adjacent the periphery thereof and passing a radio frequency heating current through the peripheral portion of the sole and welt and through said bead to thereby fuse the welt to the sole.

3. The method of fastening a plastic shoe sole to a plastic shoe welt which comprises forming an integral head on the welt adjacent the periphery thereof, said head.

4. The method of fastening a plastic shoe sole to a plas- V tic shoe welt which comprises forming an integral bead on the sole adjacent the periphery thereof, said bead facing the other of said welt and sole, placing the sole and welt in alignment with the bead therebetween, placing an electrode above the welt and a second electrode against the sole adjacent the periphery thereof and passing a radio frequency heating current through the peripheral portion of the sole and welt and through said head to 7 thereby fuse the welt to the sole.

5. The method of fastening a plastic shoe sole to a plastic shoe welt which comprises forming an integral head on the welt adjacent the periphery thereof, said head facing the other of said welt and sole, and extending throughout the entire periphery, placing the sole andwelt in alignment with the bead therebetween, placing an electrode above the welt and a second electrode against the sole adjacent the periphery thereof and passing ,a radio frequency heating current through the peripheral portion of the sole and welt and through said bead to thereby fuse the welt to the sole.

6. The method of fastening a plastic shoe sole to a plastic shoe welt which comprises forming an integral head on the sole adjacent the periphery thereof, said bead facing the other of said welt and sole, and extending throughout the entire periphery, placing the sole and welt in alignment with the bead therebetween, placing an electrode above the welt and a second electrode against the sole adjacent the periphery thereof and passing a radio frequency heating current through the peripheral portion of the sole and welt and through said head to thereby fuse the welt to the sole.

7. The method of fastening a plastic dielectric shoe sole to a plastic dielectric shoe welt which comprises forming an integral bead on at least one of the welt and sole adjacent the periphery thereof, said bead facing the other of said welt and sole, placing the sole and Welt in alignment with the bead therebetween, placing an electrode above I the welt and a second electrode against the sole adjacent the periphery thereof to form a capacitor, and passing a radio frequency heating current through said capacitor to heat the peripheral portion of the sole and welt and said bead to thereby fuse the welt to the sole.

8. The method of fastening a plastic dielectric shoe sole to a shoe upper which includes a plastic dielectric Welt, which comprises forming an integral bead on at least one of the welt and sole adjacent the periphery thereof, said bead facing the other of said welt and sole, placing the sole and welt in alignment with the bead therebetween, placing an electrode above the welt and a second electrode against the sole adjacent the periphery thereof to form a capacitor, and passing a radio frequency heating current through said capacitor to heat the periph- 6 eral portion of the sole and welt and said bead to thereby fuse the welt to the sole.

References Cited in the file of this patent UNITED STATES PATENTS Re.22,30l Pitman Apr. 13, 1943 2,298,037 Grandell Oct. 16, 1942 2,333,412 Grandell Nov. 2, 1943 2,385,554 Stratton Sept. 25, 1945 2,669,735 Iuhola Feb. 23, 1954 2,766,467 Juhola Oct. 16, 1956 2,789,295 Rollman et al. Apr. 23, 1957 2,799,034 Crowell et a1 July 16, 1957 

